The present invention relates generally to protection of remote sensing devices from interrogating radiation source and more specifically to optical devices which provide false reply signals to the interrogating source. Remote sensing devices such as missile seekers are often interrogated by radiation sources such as laser beams to determine the operating band of the sensor, its modulation rate, timing signal, chop frequency, or similar data which might be used to deteriorate the performance of the sensor. In addition the nature of these sensors is such that they have a high probability of being damaged from high amplitude incoming radiation. Thus a need arose for a device that would shield the remote sensing devices from interrogating radiation which could either damage its sensor or detect parameters of its operation or both.